Rotary cutter



Sept. 5, 1961 J. c. BOESCH, JR 2,998,689

TTTTTTTTTT ER Filed Apri l 3 l 9 57 Sept. 5, 1961 Filed April 3, 1957 J.C. BOESCH, JR

ROTARY CUTTER FIG. 7

2 Sheets-Sheet 2 FIG.6

FIG. 4

IN VEN TOR.

JOHN C. BOESCH JR ATTORNEY United States Patent 'ROTARY"CU'ITER John C.Boesch, Jr., Albany, Ga., assignor to Lilliston Implement Company,Albany, Ga, a corporation of Georgia Filed Apr. 3, 1957, Sex. No.650,503 11 Claims. (Cl. 5645.4)

This invention relates to agricultural implements and is particularlyconcerned with rotary bladed mowers, cutters, heaters and the like.

The present invention provides apparatus of simple, rugged and durablestructure, including novel and improved wheel mountings by which thecutter blade height may be quickly and easily adjusted and by which thewheel disposition with respect to the swath cut may be varied. Animportant feature of the invention also resides in the design,construction and arrangement of the cutter, heater or mowing blades bywhich a novel and improved action is provided.

Among the problems encountered in rotary bladed devices of the characterdescribed is that of the delivery of adequate force at the point ofcontact of the blades with the crop. With simple blade constructions inwhich the blade is of uniform weight and cross-section throughout itslength, it has been found that the impact force diminishes as the bladesprogresses outwardly from its hub. Obviously, the effectiveness and theefficiency of such devices is dependent upon the location of the centerof percussion or impact force and a maximum impact force is of coursedesirable at the point of engagement of the.

blade with the material to be cut, beaten or mowed. Heretofore, in orderto provide a cutting edge and to diminish overall weight of the cutter,the blades have been commonly designed with diminishing cross-sectionand hence diminishing weight outwardly from their motivating hub. Whilethe demands for lightweight and low driving power have thus been met,they have been so met at the expense of the location of the impact orpercussion force which is most effectively applied at the cutting edgewhich is located at the outer end of the blade. Such blades have alsocommonly been formed rigidly with the hub. In such case, upon contact ofthe cutter with mate rial resisting cutting action the blade is apt tobe broken or damaging shock transmitted back to the driving mechamsm.

In the light ofthe above problem, it is among the general objects of thepresent invention to provide novel and improved apparatus of thecharacter described which will effectively and efliciently carry out theoperation for which such apparatus is desired.

It is a further object of the present invention to provide a novel andimproved structural arrangement including readily adjustable means forcontrolling the elevation of the cutter with respect to the surface overwhich it travels.

The invention also includes among its objectives that of providingselective wheel disposition so as to permit wheels to be located in suchmanner as to traverse the swath already cut or to be moved to an axissubstantially normal to the axis of the cutter drive.

It is also an important object of the. present invention to provide anovel and improved blade design and construction by which a maximumimpact force is provided at the cutting edge of a rotary blade.

Another object of the invention is to provide a cutter having meansreadily yieldable upon impact of the blade with an object resisting theaction thereof so as to preclude the breaking of the blade in responseto such impact.

It is also among the objects of the present invention to provide acutter blade designed in accordance with well established rules ofmechanical force such as to effectively ntilize the laws of mass motionand centrifugal force to ICC 2 thtle end that improved effectiveness andefliciency will resu t.

Numerous other objects, features and advantages of the present inventionwill be apparent from consideration of the following specificationtakenin conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of an agricultural implement embodying thepresent invention.

FIG. 2 is a fragmentary front elevation of a device of the general typeshown in FIG. 1 illustrating in detail the mounting and construction ofthe blade element.

FIG. 3 is a fragmentary top plan view of the cutter blade of the presentinvention.

FIG. 4 is an end elevation of the blade as shown in FIG. 3.

FIG. 5 is a detail cross-sectional view of the mounting of the cutterhub as taken on line 5-5 of FIG. 3.

FIG. 6 is a detail cross-sectional view taken on line 6-6 of FIG. 3,showing the free mounting of the blade.

FIG. 7 is a bottom plan view of a modified form of the invention.

FIG. 8 is a bottom plan view of the device of FIG. 1 illustrating theselective positioning of the wheels.

With respect to the structure of the body, wheels and mounting of thepresent device, it may be generally stated that the apparatus includesdraft means by which it may 7 be secured and motivated by a conventionalfarm tractor together with drive means operable from the power takeofiof the tractor for rotating a cutter in a horizontal plane beneath thebody of the device. The apparatus also provides an improved wheelmounting and adjustment therefor, the wheels being supported on wheeltongues which in turn are mounted on an adjustably oscillating crossbar. This arrangement is such that oscillating of the cross bar willvary the angular position of the tongues and hence the vertical relationof the wheels with respect to the body to control the height of thecutter from the surface over which the device travels. This feature ofthe invention also provides ready means for converting the apparatusfrom a structure in which the wheels are disposed on either side of thebody approximately parallel to the cutter drive to one in which thewheels may be disposed in rearward trailing position with respectthereto and in the path cut by the cutter. A modified formof theinvention provides a structure with a single trailing wheel in lieu ofthe pairs of side or trailing Wheels.

The cutter construction of the present invention may be generallydefined as including a rotatably mounted cutter hub adapted to be drivenfrom a source of power above the body of the vehicle. The hub of thepreferred form of the invention is of composite construction preferablyincluding a radially outward. At the extremities of the hub arms, thereare freely mounted for unlimited rotation with respect thereto cutterblades characterized by a design incorporating added weight at theterminal end of the blade which constitutes that portion of the bladeadapted to engage the material to be cut, mowed or beaten. By'

1 provide for a maximum impact at the cutting edge of the blade where itis most effective.

Referring now particularly to FIG. 1 of the drawings, it will be seenthat the structure of the present device includes a generally horizontalfiat and rectangular body 10 suitably braced and supported by structuralangle irons as indicated at 11. Projecting forwardly from the body,

there is a draft mechanism indicated at 12 together with a gear housing13 for receiving a drive shaft 14 and communicating rotary motiontherefrom to a drive pulley 16. Rotation is imparted to the cuttermounted beneath the pair of spaced hub arms, which extend 3 body =andhereinafter discussed in detail by a pulley 16 driven by belt 17 fromthe pulley 15.

The body of the apparatus is supported from wheels -l8 mounted upon axlepintles 19 which extend outwardly from relatively horizontally disposedaxle tongues 20. Plates 21 are fixed to the ends of tongues 26 and theseplates 21' are securely mounted against plates 21 by means o'f bolts 21.The plates 21, in turn, are fixed to the *oppositeends of anoscillatingly adjustable cross bar 22. Oscillation of bar 22 iscontrolled by rigidly secured arm 23 affixed thereto. The free end ofarm 23 is secured to a traveling nut 24 mounted on the threadedextremity 25 of an adjustment crank 26. It will of course be understoodthat as the adjustment crank 26 is rotated, the nut 24*will travellongitudinally of the threaded portion 25, thus moving the arm 23 tovary the oscillated adjustment of the shaft 22 and thus swing thetongues 20 about the 'shaft as itsaxis to raise and lower the wheels 18.

It will further be noted that by the construction here presented, thewheels may be readily moved from the position shown in FIG. Isubstantially centrally of either side 'of the body to a rearwardtrailing position within the path cut by the cutter by removing thethree securing bolts '21" securing plates 21 and 21' together and byturning the tongues so that they trail the bar 22 and their pintles"point inward as shown in full lines in FIG. 8. Re-attachment of thebolts 21 through both plates in such rearwardly extending position ofthe tongues rather than the "forwardly extending position shown willcause the wheels to track the cut. By such conversion, it will be seenthat "the elevation of the body may be altered by rotation of the crank26 in the same manner as herein described with respect to suchadjustment when the wheels are in the position shown in FIG. 1.

Referring now more particularly to FIGS. 2 to 6, inclusive, it will beseen that there is mounted beneath the body 10 and on the downwardlyextending power shaft 30 driven from the pulley 16 a blade structureincluding a pair of parallel fiat blade hub pieces 31 spaced by circularhollow spacing collar 32. The blade hub pieces are rigidly secured withthe shaft 30 preferably in abutment with the inner race 33 of a shaftbearing within the housing 34. For economy and simplicity ofconstruction, design and assembly, the blade hub pieces 31 mayconveniently be formed of simple, flat strap material such as steel. Thehub pieces 31 extend radially-outwardly from the shaft 30 .for :adistance which may be dictated by the particular operation for which thedevice is designed, here shown as approximately somewhat less thanone-half of the total radial extent of the blades from the hub. At theouter rend, the blade hub pieces 31 are spaced by a collar 35 similar tothe collar 32 andare united by bolt 36 secured :by transverse pin 37together with a washer 3-8 located in a guard ring 39.

The lower end of the pin 36 is formed with a head 40 and the pin extendsupwardly therefrom through an aperture 41 at the inner terminal end 42of the blade proper. The fit of the aperture 41 over the pin 36 adjacentthe head 40 thereof is loose, permitting free rotary motion of f theblade with respect to the pin 36' and thus in free pivot- 21] relationto the hub pieces 31. Outwardly from the inner end 42, the bladeincludesan intermediate downwardly inclined portion 43 terminating in 'ahorizontal flat outwardly projecting cutting portion 44 provided on oneedge with a sharpened blade cutting or beating area 45. Indirectalignment with the area 45 and adjacent the outer terminal end 4'6 ofthe cutting portion, the blade is pro vided with a rearwardly extendingweight portion 47, here shownas a triangular rearward extension of theblade.

.By this construction, it will be seen that the portion 47 provides foramaximurn cross-section and hence maximum weight of the blade at theouter cutting end thereof. It will be understood that by the well knownbasic formula:

1 L MXO where L is the distance from the axis of suspension to thecenter of percussion, I is the moment of inertia of the blade or heaterabout its 'axis of suspension, M is total mass of the blade or beaterand X0 is the distance from the axis of suspension to the center ofgravity of the blade or beater, increasing the mass by using a largersection of material does not influence the center of percussion, butthat it is judicious positioning of additional mass to an otherwisehomogeneous consistent section of material that modifies the distanceto'the center of gravity and the moment of inertia, which repositionsthe center of percussion. It is further seen that with-the addition 'ofa given weight, the center of percussion can be brought to practicallycoincide with any practical area of impact. Thereafter, additionalweight serves primarily toincrease the kinetic energy available atthepoint of impact. This further addition is governed by the nature ofthe material being cut or beaten, hence the desired impact forsatisfactory function.

From the above consideration, it will be seen that the center ofpercussion 48 of the blade is moved outwardly to be effectively appliedat the cutting tip and that by such location of the center ofpercussion, the impact is maximum at the place where such impact is tobe applied. In considering this feature of the invention, it will ofcourse be understood that the invention is not limited to the specificstructural arrangement by which the weight of the bladeis .broughtintoalignment with the cutting tip portion. It will also benoted inconsidering this feature of theinvention that the provision of increasedweight at the outer terminal end of the blade providesfor increasedeffectiveness and efiiciency of centrifugal forces applied to the blade,and hence it ispossible to provide the free loose mounting of the bladeproper on the outer'portion of the hub piecessoas to permit the .bladeto yield in its mounting with respect to the. hub upon impact with anonyielding object. Nevertheless, by virtue of the weighted tip of theblade, centrifugal'force will maintain the blade in alignment with thehub pieces to effectively maintain-a cutting disposition thereof.

By reference to FIGS. Z'and 7of the drawings, it will be noted that asan alternative construction, a single centrally located wheel 50 may bemounted at the 'outwardly,extending'frusto-triangular portion 51 of thebody 10 From the foregoing, it will be seen that the invention providesva simple, rugged and durable structure together with a novel andimproved wheel adjusting means, and a blade structure of new andimproved design effectively and efiiciently distributing the weightthereof to provide registration of the center of percussion with thecutting portion of the blade so as to insure the best impact pressure.It will be noted that the invention is not limited nor confined to thespecific structural details here presented, and thus numerous changes,modifications and the full use of equivalents may be resorted to in thepractice of the invention without departing from the'spirit or scopethereof as'defined in the appended claims.

I claim: a

1. In a rotary blade'for an agricultural apparatus, a cutting area'onsaid blade,'and means on said blade locating the center of percussion atthe cutter area thereof.

2. In a rotary blade for an agricultural apparatus, a cutting areaonsaid blade, and means on said bladelocating the center of percussionat the cutting area thereof, said means compzisingan increasev of blademass approximately at the cutting area.

3. In a rotary blade for an agricultural apparatus-acutting area on saidblade, and. means on said blade locating the center of percussion at thecutting area, said means comprising tan increase of -blade massapproximately at the cutting area provided by an increase in blade widthat such area.

4. In a rotary blade for an agricultural apparatus, a cutting area onsaid blade, and means on said blade 1ocating the center of percussion atthe cutting area, said means comprising an increase of blade massapproximately at the cutting area provided by an increase in blade widthformed by an extension of the blade behind the cutting area.

5. In a rotary blade for an agricultural apparatus, a cutting tip onsaid blade, and means on said blade locating the center of percussion atthe cutting tip, said means comprising an increase of blade massapproximately at the cutting tip thereof provided by an increase inblade width formed by a triangular extension of the blade behind saidcutting tip.

6. A rotary blade assembly for agricultural apparatus including a drivenhub comprising spaced hub pieces, and a blade member pivotally mountedbeneath said hub pieces for disposition under centrifugal forcesubstantially radially outward of said hub, said blade member having anintermediate downwardly inclined portion adjacent said pivotally mountedportion and a horizontally projecting portion outwardly thereof.

7. A rotary blade assembly for agricultural apparatus including a drivenhub comprising spaced fiat strap hub pieces, and a blade memberpivotally mounted beneath said hub pieces for disposition undercentrifugal force substantially radially outward of said hub, said blademember having an intermediate downwardly inclined portion adjacent saidpivotally mounted portion and a horizontally projecting portionoutwardly thereof.

8. A rotary blade assembly for agricultural apparatus including a drivenhub comprising spaced fiat strap hub pieces, and a pair of blade memberspivotally mounted respectively beneath said hub pieces for dispositionunder centrifugal force substantially radially outward of said hub,cutting tips on said blade members, said members being of increased massat their extremities sufiiciently to bring the center of percussionwithin the cutting tips of said blade members, said blade members havingintermediate downwardly inclined portions adjacent said pivotallymounted portions and horizontally projecting portions outwardly thereof.

9. In an agricultural apparatus, a body, wheels supporting said body,draft means for said body, a power drive, a vertical shaft driven bysaid power drive and extending 6 through said body, and a rotary bladeassembly mounted on said shaft below said body, said blade assemblyinclud ing a hub and blades loosely pivoted to said hub, a cutting endon each said blade, each blade including a weight at mounted on saidshaft below said body, said blade assem- I bly including a hub andblades loosely pivoted to said hub, a cutting tip on each said blade,each blade including a weight at the cutting tip thereof formed by aportion of increased width of sufficient magnitude to locate the centerof percussion at the impact area of the cutting tip of said blade.

11. In an agricultural apparatus, a body, wheels supporting said bodymounted upon angularly adjustable tongues secured to an oscillatinglyadjustable bar secured transversely of said body, draft means for saidbody, a power drive, a vertical shaft driven by said power drive andextending through said body, and a rotary blade assembly mounted on saidshaft below said body, said blade assembly including a hub and bladesloosely pivoted to said hub, an outer cutting tip on each said bladeeach blade including a weight at the outer cutting tip thereof formed bya portion of increased cross-section suflicient to locate the center ofpercussion substantially at the impact area of the cutting tip of saidblade.

References Cited in the file of this patent UNITED STATES PATENTS

